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kmp

//Achen
#include<algorithm>
#include<iostream>
#include<cstring>
#include<cstdlib>
#include<vector>
#include<cstdio>
#include<queue>
#include<cmath>
#include<set>
#define For(i,a,b) for(int i=(a);i<=(b);i++)
#define Rep(i,a,b) for(int i=(a);i>=(b);i--)
const int N=1000007;
typedef long long LL; 
using namespace std;
int n,m,nxt[N],ans[N];
char s1[N],s2[N];

template<typename T> void read(T &x) {
    char ch=getchar(); x=0; T f=1;
    while(ch!='-'&&(ch<'0'||ch>'9')) ch=getchar();
    if(ch=='-') f=-1,ch=getchar();
    for(;ch>='0'&&ch<='9';ch=getchar()) x=x*10+ch-'0'; x*=f;
}

void make_nxt(char s[],int n) {
    for(int i=1,k=0;i<n;i++) {
        while(k&&s[i]!=s[k]) k=nxt[k-1];
        if(s[i]==s[k]) k++;
        nxt[i]=k;
    }
}

void qry(char s[],int n,char p[],int m) {
    for(int i=0,k=0;i<n;i++) {
        while(k&&s[i]!=p[k]) k=nxt[k-1];
        if(s[i]==p[k]) k++;
        if(k==m) ans[++ans[0]]=i-m+2;
    }
}

int main() {
#ifdef DEBUG
    freopen(".in","r",stdin);
    freopen(".out","w",stdout);
#endif
    scanf("%s",s1);
    scanf("%s",s2);
    n=strlen(s1); 
    m=strlen(s2);
    make_nxt(s2,m);
    qry(s1,n,s2,m);
    For(i,1,ans[0]) printf("%d
",ans[i]);
    For(i,0,m-1) printf("%d ",nxt[i]); puts("");
    return 0;
}
/*
ABABABC
ABA
*/
View Code

 

AC自动机

简单版

 1 //Achen
 2 #include<algorithm>
 3 #include<iostream>
 4 #include<cstring>
 5 #include<cstdlib>
 6 #include<vector>
 7 #include<cstdio>
 8 #include<queue>
 9 #include<cmath>
10 #include<set>
11 #define For(i,a,b) for(int i=(a);i<=(b);i++)
12 #define Rep(i,a,b) for(int i=(a);i>=(b);i--)
13 const int N=1e6+7;
14 typedef long long LL; 
15 using namespace std;
16 int n,ans;
17 char s[N];
18 
19 template<typename T> void read(T &x) {
20     char ch=getchar(); x=0; T f=1;
21     while(ch!='-'&&(ch<'0'||ch>'9')) ch=getchar();
22     if(ch=='-') f=-1,ch=getchar();
23     for(;ch>='0'&&ch<='9';ch=getchar()) x=x*10+ch-'0'; x*=f;
24 }
25 
26 int ch[N][26],fail[N],w[N],rt,tot;
27 void insert() {
28     if(!rt) rt=++tot;
29     int len=strlen(s),x=rt;
30     For(i,0,len-1) {
31         int c=s[i]-'a';
32         if(!ch[x][c]) ch[x][c]=++tot;
33         x=ch[x][c];
34     }
35     w[x]++;
36 }
37 
38 queue<int>que;
39 void get_fail() {
40     que.push(rt);
41     while(!que.empty()) {
42         int x=que.front();
43         que.pop();
44         For(i,0,25) if(ch[x][i]) {
45             int y=ch[x][i];
46             if(x==rt) fail[y]=rt;
47             else {
48                 int z=fail[x];
49                 while(fail[z]&&!ch[z][i]) z=fail[z];
50                 if(ch[z][i]) fail[y]=ch[z][i];
51                 else fail[y]=rt;
52             }
53             que.push(y);
54         }
55     }
56 }
57 
58 void qry() {
59     int len=strlen(s),x=rt;
60     For(i,0,len-1) {
61         int c=s[i]-'a';
62         while(!ch[x][c]&&fail[x]) x=fail[x];
63         if(ch[x][c]) {
64             x=ch[x][c];
65             if(w[x]) ans+=w[x];
66             w[x]=0;
67             int y=fail[x];
68             while(y&&w[y]) {
69                 ans+=w[y];
70                 w[y]=0;
71                 y=fail[y];
72             }
73         }
74     }
75 }
76 
77 int main() {
78 #ifdef DEBUG
79     freopen(".in","r",stdin);
80     freopen(".out","w",stdout);
81 #endif
82     read(n);
83     For(i,1,n) {
84         scanf("%s",s);
85         insert();
86     }
87     get_fail();
88     scanf("%s",s);
89     qry();
90     printf("%d
",ans);
91     return 0;
92 }
93 /*
94 2
95 a
96 aa
97 aa
98 */
View Code

加强版

  1 //Achen
  2 #include<algorithm>
  3 #include<iostream>
  4 #include<cstring>
  5 #include<cstdlib>
  6 #include<vector>
  7 #include<cstdio>
  8 #include<queue>
  9 #include<cmath>
 10 #include<set>
 11 #define For(i,a,b) for(int i=(a);i<=(b);i++)
 12 #define Rep(i,a,b) for(int i=(a);i>=(b);i--)
 13 const int N=1e6+7;
 14 typedef long long LL; 
 15 using namespace std;
 16 int n,ansmx,ans[N],tid[157];
 17 char s[N],ss[157][77];
 18 
 19 template<typename T> void read(T &x) {
 20     char ch=getchar(); x=0; T f=1;
 21     while(ch!='-'&&(ch<'0'||ch>'9')) ch=getchar();
 22     if(ch=='-') f=-1,ch=getchar();
 23     for(;ch>='0'&&ch<='9';ch=getchar()) x=x*10+ch-'0'; x*=f;
 24 }
 25 
 26 int ch[N][26],fail[N],rt,tot;
 27 void insert(int id) {
 28     if(!rt) rt=++tot;
 29     int len=strlen(ss[id]),x=rt;
 30     For(i,0,len-1) {
 31         int c=ss[id][i]-'a';
 32         if(!ch[x][c]) ch[x][c]=++tot;
 33         x=ch[x][c];
 34     }
 35     tid[id]=x;
 36 }
 37 
 38 queue<int>que;
 39 int sta[N],top;
 40 void get_fail() {
 41     que.push(rt);
 42     while(!que.empty()) {
 43         int x=que.front();
 44         que.pop();
 45         For(i,0,25) if(ch[x][i]) {
 46             int y=ch[x][i];
 47             if(x==rt) fail[y]=rt;
 48             else {
 49                 int z=fail[x];
 50                 while(fail[z]&&!ch[z][i]) z=fail[z];
 51                 if(ch[z][i]) fail[y]=ch[z][i];
 52                 else fail[y]=rt;
 53             }
 54             que.push(y);
 55             sta[++top]=y;
 56         }
 57     }
 58 }
 59 
 60 int cnt[N];
 61 void qry() {
 62     int len=strlen(s),x=rt;
 63     For(i,0,len-1) {
 64         int c=s[i]-'a';
 65         while(!ch[x][c]&&fail[x]) x=fail[x];
 66         if(ch[x][c]) {
 67             x=ch[x][c];
 68             cnt[x]++;
 69         }
 70     }
 71     while(top) {
 72         int x=sta[top--];
 73         cnt[fail[x]]+=cnt[x];
 74     }
 75     ansmx=0; ans[0]=0;
 76     For(i,1,n) ansmx=max(ansmx,cnt[tid[i]]); 
 77     For(i,1,n) if(ansmx==cnt[tid[i]]) ans[++ans[0]]=i;
 78     printf("%d
",ansmx);
 79     For(i,1,ans[0]) puts(ss[ans[i]]);
 80 }
 81 
 82 int main() {
 83 #ifdef DEBUG
 84     freopen(".in","r",stdin);
 85     freopen(".out","w",stdout);
 86 #endif
 87     while(scanf("%d",&n)) {
 88         if(!n) break;
 89         memset(ch,0,sizeof(ch));
 90         memset(cnt,0,sizeof(cnt));
 91         tot=rt=top=0;
 92         For(i,1,n) {
 93             scanf("%s",ss[i]);
 94             insert(i);
 95         }
 96         get_fail();
 97         scanf("%s",s);
 98         qry();
 99     }
100     return 0;
101 }
102 /*
103 2
104 aba
105 bab
106 ababababac
107 6
108 beta
109 alpha
110 haha
111 delta
112 dede
113 tata
114 dedeltalphahahahototatalpha
115 0
116 */
View Code

 

manacher

//Achen
#include<algorithm>
#include<iostream>
#include<cstring>
#include<cstdlib>
#include<vector>
#include<cstdio>
#include<queue>
#include<cmath>
#include<set>
#define For(i,a,b) for(int i=(a);i<=(b);i++)
#define Rep(i,a,b) for(int i=(a);i>=(b);i--)
const int N=21000007;
typedef long long LL; 
typedef double db;
using namespace std;
char ss[N],s[N];
int len,n,rad[N],ans;

template<typename T> void read(T &x) {
    char ch=getchar(); x=0; T f=1;
    while(ch!='-'&&(ch<'0'||ch>'9')) ch=getchar();
    if(ch=='-') f=-1,ch=getchar();
    for(;ch>='0'&&ch<='9';ch=getchar()) x=x*10+ch-'0'; x*=f;
}

void manacher(char s[],int n) {
    for(int i=1,k=0,j;i<n;) {
        while(s[i-k-1]==s[i+k+1]) k++;
        rad[i]=k; ans=max(ans,k);
        for(j=1;j<=k&&rad[i-j]!=rad[i]-j;j++) 
            rad[i+j]=min(rad[i-j],rad[i]-j);
        i+=j;
        k=max(0,k-j);
    }
}

int main() {
#ifdef DEBUG
    freopen(".in","r",stdin);
    freopen(".out","w",stdout);
#endif
    scanf("%s",ss);
    len=strlen(ss);
    s[n++]='*';
    For(i,0,len) {
        s[n++]='#';
        s[n++]=ss[i];
    } 
    s[n++]='#';
    s[n++]='&';
    manacher(s,n);
    printf("%d
",ans);
    return 0;
}
View Code

 

后缀数组

 1 //Achen
 2 #include<algorithm>
 3 #include<iostream>
 4 #include<cstring>
 5 #include<cstdlib>
 6 #include<vector>
 7 #include<cstdio>
 8 #include<queue>
 9 #include<cmath>
10 #include<set>
11 #define For(i,a,b) for(int i=(a);i<=(b);i++)
12 #define Rep(i,a,b) for(int i=(a);i>=(b);i--)
13 const int N=2e6+7;
14 typedef long long LL; 
15 typedef double db;
16 using namespace std;
17 int n,sa[N],rak[N],h[N];
18 char s[N];
19 
20 template<typename T> void read(T &x) {
21     char ch=getchar(); x=0; T f=1;
22     while(ch!='-'&&(ch<'0'||ch>'9')) ch=getchar();
23     if(ch=='-') f=-1,ch=getchar();
24     for(;ch>='0'&&ch<='9';ch=getchar()) x=x*10+ch-'0'; x*=f;
25 }
26 
27 void make_hight() {
28     For(i,0,n-1) rak[sa[i]]=i;
29     for(int i=0,k=0;i<n;i++) {
30         if(!rak[i]) continue;
31         if(k) k--;
32         int j=sa[rak[i]-1];
33         while(s[i+k]==s[j+k]) k++;
34         h[rak[i]-1]=k;
35     }
36 }
37 
38 int cmp(int a,int b,int k,int y[]) {
39     int o1=a+k>=n?-1:y[a+k];
40     int o2=b+k>=n?-1:y[b+k];
41     return o1==o2&&y[a]==y[b];
42 }
43 
44 void make_sa() {
45     static int t1[N],t2[N],c[N];
46     int *x=t1,*y=t2,p,m='z'+1;
47     For(i,0,m-1) c[i]=0;
48     For(i,0,n-1) c[x[i]=s[i]]++;
49     For(i,1,m-1) c[i]+=c[i-1];
50     Rep(i,n-1,0) sa[--c[x[i]]]=i;
51     for(int k=1;k<=n;k<<=1) {
52         p=0;
53         For(i,n-k,n-1) y[p++]=i;
54         For(i,0,n-1) if(sa[i]>=k) y[p++]=sa[i]-k;
55         For(i,0,m-1) c[i]=0;
56         For(i,0,n-1) c[x[y[i]]]++;
57         For(i,1,m-1) c[i]+=c[i-1];
58         Rep(i,n-1,0) sa[--c[x[y[i]]]]=y[i];
59         swap(x,y); x[sa[0]]=0; p=1;
60         For(i,1,n-1) 
61             x[sa[i]]=cmp(sa[i],sa[i-1],k,y)?p-1:p++;
62         if(p>=n) break;
63         m=p;
64     }
65     make_hight();
66 }
67 
68 int main() {
69 #ifdef DEBUG
70     freopen(".in","r",stdin);
71     freopen(".out","w",stdout);
72 #endif
73     scanf("%s",s);
74     n=strlen(s);
75     make_sa();
76     For(i,0,n-1) printf("%d ",sa[i]+1);
77     return 0;
78 }
View Code

 

后缀自动机

//Achen
#include<algorithm>
#include<iostream>
#include<cstring>
#include<cstdlib>
#include<vector>
#include<cstdio>
#include<queue>
#include<cmath>
#include<set>
#define For(i,a,b) for(int i=(a);i<=(b);i++)
#define Rep(i,a,b) for(int i=(a);i>=(b);i--)
const int N=2e6+7;
typedef long long LL; 
typedef double db;
using namespace std;
int n,rt,fa[N],sz[N],l[N],ch[N][26],p,np,last,tot;
LL ans;
char s[N];

template<typename T> void read(T &x) {
    char ch=getchar(); x=0; T f=1;
    while(ch!='-'&&(ch<'0'||ch>'9')) ch=getchar();
    if(ch=='-') f=-1,ch=getchar();
    for(;ch>='0'&&ch<='9';ch=getchar()) x=x*10+ch-'0'; x*=f;
}

void insert(int c) {
    if(!rt) { rt=++tot; last=rt; }
    p=last; np=++tot; last=np;
    l[np]=l[p]+1; sz[np]++;
    for(;p&&!ch[p][c];p=fa[p]) ch[p][c]=np;
    if(!p) fa[np]=rt;
    else {
        int q=ch[p][c];
        if(l[q]==l[p]+1) fa[np]=q;
        else {
            int nq=++tot; l[nq]=l[p]+1;
            memcpy(ch[nq],ch[q],sizeof(ch[q]));
            fa[nq]=fa[q]; fa[q]=fa[np]=nq;
            for(;p&&ch[p][c]==q;p=fa[p]) ch[p][c]=nq;
        } 
    }
}

void solve() {
    static int sa[N],c[N];
    For(i,1,tot) c[l[i]]++;
    For(i,1,n) c[i]+=c[i-1];
    For(i,1,tot) sa[c[l[i]]--]=i;
    Rep(i,tot,1) {
        int x=sa[i];
        sz[fa[x]]+=sz[x];
        if(sz[x]>1) ans=max(ans,(LL)sz[x]*l[x]);
    }
}

int main() {
#ifdef DEBUG
    freopen(".in","r",stdin);
    freopen(".out","w",stdout);
#endif
    scanf("%s",s);
    n=strlen(s);
    For(i,0,n-1) insert(s[i]-'a');
    solve();
    printf("%lld
",ans);
    return 0;
}
View Code

 

回文自动机

 1 //Achen
 2 #include<algorithm>
 3 #include<iostream>
 4 #include<cstring>
 5 #include<cstdlib>
 6 #include<vector>
 7 #include<cstdio>
 8 #include<queue>
 9 #include<cmath>
10 #include<set>
11 #define For(i,a,b) for(int i=(a);i<=(b);i++)
12 #define Rep(i,a,b) for(int i=(a);i>=(b);i--)
13 const int N=1e5+7; 
14 typedef long long LL;
15 typedef double db;
16 using namespace std;
17 char s[N];
18 int ans,n,last,tot,rt1,rt2,ch[N][26],len[N],fail[N],l[N],r[N],sz[N];
19 
20 void init() {
21     tot=0; len[rt1=0]=0; len[rt2=++tot]=-1;
22     fail[rt1]=rt2; last=rt1;
23       memset(ch,0,sizeof(ch));
24 }
25 
26 void insert(int n,int c,int p[]) {
27     int x=last,y;
28     for(;s[n]!=s[n-len[x]-1];x=fail[x]);
29     if(!ch[x][c]) {
30         len[++tot]=len[x]+2;
31         for(y=fail[x];s[n]!=s[n-len[y]-1];y=fail[y]);
32         fail[tot]=ch[y][c];
33         ch[x][c]=tot;
34     }
35     last=ch[x][c];
36     sz[last]++;
37     p[n]=len[last];
38 }
39 
40 int main() {
41 #ifdef DEBUG
42     freopen(".in","r",stdin);
43     freopen(".out","w",stdout);
44 #endif
45     scanf("%s",s);
46     n=strlen(s);  
47     init();
48     for(int i=0;i<n;i++) 
49         insert(i,s[i]-'a',l);
50     for(int i=0;i<=n/2;i++) swap(s[i],s[n-i-1]);
51     init();
52     for(int i=0;i<n;i++) insert(i,s[i]-'a',r);
53     for(int i=0;i<n-1;i++) 
54         ans=max(ans,r[i]+l[n-(i+1)-1]);
55     printf("%d
",ans);
56     return 0;
57 }
View Code

 

原文地址:https://www.cnblogs.com/Achenchen/p/8776309.html